MAIDUGURI, Nigeria — Many survivors of brutal clashes between soldiers and Islamist gunmen last week in a remote Nigerian town are still in hiding, an emergency official said Friday, as police confirmed that fresh attacks by the insurgents in another area left 25 people dead.

The violence in the town of Baga last week was likely the deadliest-ever episode in the Boko Haram conflict, which has included scores of attacks across northern and central Nigeria since 2009.

As rescue workers struggled to care for the victims of Baga, trying to encourage them to return to a home which was ravaged by fire, suspected Boko Haram gunmen carried out yet another attack in a bordering state.

On Thursday, the Islamists stormed several police posts in the town of Gashua, the police commissioner of Yobe state, Sanusi Rufai told journalists.

Gun battles broke out that killed "five policemen and 20 gunmen," he added. Nigeria's military had previously given a toll of seven dead in Thursday's clash.

Aside from the raids on the police, a common Boko Haram target, Rufai said the gunmen also robbed a bank and "carted away nine million naira ($57,000 44,000 euros) and two vehicles".

In Baga, an area with little mobile phone coverage near Lake Chad, the National Emergency Management Agency (NEMA) has set up 10 camps for those displaced and is trying to distribute relief materials after fierce fighting last Friday that killed 187 people.

But the work has been complicated in a community traumatised by the carnage, NEMA spokesman Manzo Ezekiel told AFP. "The people were initially sceptical," he said. "They weren't sceptical because of NEMA but at first they ran away because NEMA came with soldiers," Ezekiel added. "Many people are still in hiding."

Soldiers have been accused of firing indiscriminately on civilians while setting fires to scores of homes and a market after gun battles with Islamists broke out. Thousands of people were reported to have fled to the bush outside of Baga while trying to escape the bloodshed.

The military has fiercely denied any wrongdoing and has claimed that only 37 people were killed.

They said the sweeping fires, estimated to have destroyed nearly half the town, were caused by insurgent grenade and gunfire.

"Part of our work there is to build confidence," the NEMA spokesman said. "We need to show people that what we have now in Baga is assistance, not any more attacks."

The Red Cross has also deployed to the fishing town, but said it is still assessing the scale of the devastation.

The regional Governor Kashim Shettima has called the events in Baga "barbaric."

Northeast Nigeria has been the epicentre of the Boko Haram insurgency, which is estimated to have cost more than 3,000 lives, including killings by the security forces.

The group has said it wants to create an Islamic state in northern Nigeria, where most people are Muslim. The southern half of the country, Africa's most populous and top oil producer, is mainly Christian.